package com.xmb.quick.constant;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * 验证码生成类
 * @author owner
 *
 */
public class RandomValidateCode {    
	
	public static final String RANDOMCODEKEY = "RANDMVALIDATECDEKEY";//放到session中的key 
	private Random random = new Random();    
	private String randString = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生的字符串       
	private int width = 100;//图片宽    
	private int height = 40;//图片高    
	private int lineSize = 30;//干扰线数量    
	private int stringNum = 4;//随机产生字符数量   
	
	/*
	 * 获得字体   
	 */
	private Font getFont(){        
		return new Font("Fixedsys",Font.CENTER_BASELINE,25);    
	}    
	/*
	 * 获得颜色 
	 */
	private Color getRandColor(int fc,int bc){        
		if(fc > 255){            
			fc = 255;
		}
		if(bc > 255){
			bc = 255;  
		}
		int r = fc + random.nextInt(bc-fc-16);        
		int g = fc + random.nextInt(bc-fc-14);        
		int b = fc + random.nextInt(bc-fc-18);        
		return new Color(r,g,b);    
	}   
	/*
	 * 生成随机图片    
	 */
	public void getRandcode(HttpServletRequest request,HttpServletResponse response) {       
		
		HttpSession session = request.getSession();//BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类       
		BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);        
		Graphics g = image.getGraphics();//产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作        
		g.fillRect(0, 0, width, height);        
		g.setFont(new Font("Times New Roman",Font.ROMAN_BASELINE,25));        
		g.setColor(getRandColor(110, 133)); //绘制干扰线       
		
		for(int i=0;i<=lineSize;i++){      
			drowLine(g);        
		}
		//绘制随机字符        
		String randomString = "";        
		for(int i=1;i<=stringNum;i++){            
			randomString=drowString(g,randomString,i);        
		}
		session.removeAttribute(RANDOMCODEKEY);  
		session.setAttribute(RANDOMCODEKEY, randomString);
		g.dispose();       
		try {            
			ImageIO.write(image, "JPEG", response.getOutputStream());//将内存中的图片通过流动形式输出到客户端        
		} catch (Exception e) {            
			e.printStackTrace();        
		}    
	}    
	/*
	 * 绘制字符串    
	 */
	private String drowString(Graphics g,String randomString,int i){        
		g.setFont(getFont());        
		g.setColor(new Color(random.nextInt(101),random.nextInt(111),random.nextInt(121)));        
		String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));        
		randomString +=rand;        
		g.translate(random.nextInt(3), random.nextInt(3));        
		g.drawString(rand, 13*i, 30);        
		return randomString;    
	}    
	/* 
	 * 绘制干扰线
	 */    
	private void drowLine(Graphics g){        
		int x = random.nextInt(width);        
		int y = random.nextInt(height);        
		int xl = random.nextInt(13);        
		int yl = random.nextInt(15);        
		g.drawLine(x, y, x+xl, y+yl);    
	}   
	/*   
	 *  获取随机的字符   
	 */    
	public String getRandomString(int num){        
		return String.valueOf(randString.charAt(num));    
	}
}
		
			
			